Added lossless encoding to WavPack library. Also made a few changes to

decoding stuff in preparation for future optimization and eliminated all tabs.


git-svn-id: svn://svn.rockbox.org/rockbox/trunk@7009 a1c6a512-1295-4272-9138-f99709370657

1 files changed, 450 insertions, 0 deletions

diff --git a/apps/codecs/libwavpack/pack.c b/apps/codecs/libwavpack/pack.c
new file mode 100644
index 0000000..e695388
--- /dev/null
+++ b/apps/codecs/libwavpack/pack.c
@@ -0,0 +1,450 @@
+////////////////////////////////////////////////////////////////////////////
+//                           **** WAVPACK ****                            //
+//                  Hybrid Lossless Wavefile Compressor                   //
+//              Copyright (c) 1998 - 2005 Conifer Software.               //
+//                          All Rights Reserved.                          //
+//      Distributed under the BSD Software License (see license.txt)      //
+////////////////////////////////////////////////////////////////////////////
+
+// pack.c
+
+// This module actually handles the compression of the audio data, except for
+// the entropy coding which is handled by the words? modules. For efficiency,
+// the conversion is isolated to tight loops that handle an entire buffer.
+
+#include "wavpack.h"
+
+#include <string.h>
+
+// This flag provides faster encoding speed at the expense of more code. The
+// improvement applies to 16-bit stereo lossless only.
+
+//////////////////////////////// local tables ///////////////////////////////
+
+// These two tables specify the characteristics of the decorrelation filters.
+// Each term represents one layer of the sequential filter, where positive
+// values indicate the relative sample involved from the same channel (1=prev),
+// 17 & 18 are special functions using the previous 2 samples, and negative
+// values indicate cross channel decorrelation (in stereo only).
+
+static const char default_terms [] = { 18,18,2,3,-2,0 };
+static const char high_terms [] = { 18,18,2,3,-2,18,2,4,7,5,3,6,8,-1,18,2,0 };
+static const char fast_terms [] = { 17,17,0 };
+
+///////////////////////////// executable code ////////////////////////////////
+
+// This function initializes everything required to pack WavPack bitstreams
+// and must be called BEFORE any other function in this module.
+
+void pack_init (WavpackContext *wpc)
+{
+    WavpackStream *wps = &wpc->stream;
+    ulong flags = wps->wphdr.flags;
+    struct decorr_pass *dpp;
+    const char *term_string;
+    int ti;
+
+    wps->sample_index = 0;
+    CLEAR (wps->decorr_passes);
+
+    if (wpc->config.flags & CONFIG_HIGH_FLAG)
+        term_string = high_terms;
+    else if (wpc->config.flags & CONFIG_FAST_FLAG)
+        term_string = fast_terms;
+    else
+        term_string = default_terms;
+
+    for (dpp = wps->decorr_passes, ti = 0; term_string [ti]; ti++)
+        if (term_string [ti] >= 0 || (flags & CROSS_DECORR)) {
+            dpp->term = term_string [ti];
+            dpp++->delta = 2;
+        }
+        else if (!(flags & MONO_FLAG)) {
+            dpp->term = -3;
+            dpp++->delta = 2;
+        }
+
+    wps->num_terms = dpp - wps->decorr_passes;
+    init_words (wps);
+}
+
+// Allocate room for and copy the decorrelation terms from the decorr_passes
+// array into the specified metadata structure. Both the actual term id and
+// the delta are packed into single characters.
+
+static void write_decorr_terms (WavpackStream *wps, WavpackMetadata *wpmd)
+{
+    int tcount = wps->num_terms;
+    struct decorr_pass *dpp;
+    char *byteptr;
+
+    byteptr = wpmd->data = wpmd->temp_data;
+    wpmd->id = ID_DECORR_TERMS;
+
+    for (dpp = wps->decorr_passes; tcount--; ++dpp)
+        *byteptr++ = ((dpp->term + 5) & 0x1f) | ((dpp->delta << 5) & 0xe0);
+
+    wpmd->byte_length = byteptr - (char *) wpmd->data;
+}
+
+// Allocate room for and copy the decorrelation term weights from the
+// decorr_passes array into the specified metadata structure. The weights
+// range +/-1024, but are rounded and truncated to fit in signed chars for
+// metadata storage. Weights are separate for the two channels
+
+static void write_decorr_weights (WavpackStream *wps, WavpackMetadata *wpmd)
+{
+    int tcount = wps->num_terms;
+    struct decorr_pass *dpp;
+    char *byteptr;
+
+    byteptr = wpmd->data = wpmd->temp_data;
+    wpmd->id = ID_DECORR_WEIGHTS;
+
+    for (dpp = wps->decorr_passes; tcount--; ++dpp) {
+        dpp->weight_A = restore_weight (*byteptr++ = store_weight (dpp->weight_A));
+
+        if (!(wps->wphdr.flags & MONO_FLAG))
+            dpp->weight_B = restore_weight (*byteptr++ = store_weight (dpp->weight_B));
+    }
+
+    wpmd->byte_length = byteptr - (char *) wpmd->data;
+}
+
+// Allocate room for and copy the decorrelation samples from the decorr_passes
+// array into the specified metadata structure. The samples are signed 32-bit
+// values, but are converted to signed log2 values for storage in metadata.
+// Values are stored for both channels and are specified from the first term
+// with unspecified samples set to zero. The number of samples stored varies
+// with the actual term value, so those must obviously be specified before
+// these in the metadata list. Any number of terms can have their samples
+// specified from no terms to all the terms, however I have found that
+// sending more than the first term's samples is a waste. The "wcount"
+// variable can be set to the number of terms to have their samples stored.
+
+static void write_decorr_samples (WavpackStream *wps, WavpackMetadata *wpmd)
+{
+    int tcount = wps->num_terms, wcount = 1, temp;
+    struct decorr_pass *dpp;
+    uchar *byteptr;
+
+    byteptr = wpmd->data = wpmd->temp_data;
+    wpmd->id = ID_DECORR_SAMPLES;
+
+    for (dpp = wps->decorr_passes; tcount--; ++dpp)
+        if (wcount) {
+            if (dpp->term > MAX_TERM) {
+                dpp->samples_A [0] = exp2s (temp = log2s (dpp->samples_A [0]));
+                *byteptr++ = temp;
+                *byteptr++ = temp >> 8;
+                dpp->samples_A [1] = exp2s (temp = log2s (dpp->samples_A [1]));
+                *byteptr++ = temp;
+                *byteptr++ = temp >> 8;
+
+                if (!(wps->wphdr.flags & MONO_FLAG)) {
+                    dpp->samples_B [0] = exp2s (temp = log2s (dpp->samples_B [0]));
+                    *byteptr++ = temp;
+                    *byteptr++ = temp >> 8;
+                    dpp->samples_B [1] = exp2s (temp = log2s (dpp->samples_B [1]));
+                    *byteptr++ = temp;
+                    *byteptr++ = temp >> 8;
+                }
+            }
+            else if (dpp->term < 0) {
+                dpp->samples_A [0] = exp2s (temp = log2s (dpp->samples_A [0]));
+                *byteptr++ = temp;
+                *byteptr++ = temp >> 8;
+                dpp->samples_B [0] = exp2s (temp = log2s (dpp->samples_B [0]));
+                *byteptr++ = temp;
+                *byteptr++ = temp >> 8;
+            }
+            else {
+                int m = 0, cnt = dpp->term;
+
+                while (cnt--) {
+                    dpp->samples_A [m] = exp2s (temp = log2s (dpp->samples_A [m]));
+                    *byteptr++ = temp;
+                    *byteptr++ = temp >> 8;
+
+                    if (!(wps->wphdr.flags & MONO_FLAG)) {
+                        dpp->samples_B [m] = exp2s (temp = log2s (dpp->samples_B [m]));
+                        *byteptr++ = temp;
+                        *byteptr++ = temp >> 8;
+                    }
+
+                    m++;
+                }
+            }
+
+            wcount--;
+        }
+        else {
+            CLEAR (dpp->samples_A);
+            CLEAR (dpp->samples_B);
+        }
+
+    wpmd->byte_length = byteptr - (uchar *) wpmd->data;
+}
+
+// Allocate room for and copy the configuration information into the specified
+// metadata structure. Currently, we just store the upper 3 bytes of
+// config.flags and only in the first block of audio data. Note that this is
+// for informational purposes not required for playback or decoding (like
+// whether high or fast mode was specified).
+
+static void write_config_info (WavpackContext *wpc, WavpackMetadata *wpmd)
+{
+    char *byteptr;
+
+    byteptr = wpmd->data = wpmd->temp_data;
+    wpmd->id = ID_CONFIG_BLOCK;
+    *byteptr++ = (char) (wpc->config.flags >> 8);
+    *byteptr++ = (char) (wpc->config.flags >> 16);
+    *byteptr++ = (char) (wpc->config.flags >> 24);
+    wpmd->byte_length = byteptr - (char *) wpmd->data;
+}
+
+// Pack an entire block of samples (either mono or stereo) into a completed
+// WavPack block. This function is actually a shell for pack_samples() and
+// performs tasks like handling any shift required by the format, preprocessing
+// of floating point data or integer data over 24 bits wide, and implementing
+// the "extra" mode (via the extra?.c modules). It is assumed that there is
+// sufficient space for the completed block at "wps->blockbuff" and that
+// "wps->blockend" points to the end of the available space. A return value of
+// FALSE indicates an error.
+
+static int pack_samples (WavpackContext *wpc, long *buffer);
+
+int pack_block (WavpackContext *wpc, long *buffer)
+{
+    WavpackStream *wps = &wpc->stream;
+    ulong flags = wps->wphdr.flags, sflags = wps->wphdr.flags;
+    ulong sample_count = wps->wphdr.block_samples;
+
+    if (flags & SHIFT_MASK) {
+        int shift = (flags & SHIFT_MASK) >> SHIFT_LSB;
+        int mag = (flags & MAG_MASK) >> MAG_LSB;
+        ulong cnt = sample_count;
+        long *ptr = buffer;
+
+        if (flags & MONO_FLAG)
+            while (cnt--)
+                *ptr++ >>= shift;
+        else
+            while (cnt--) {
+                *ptr++ >>= shift;
+                *ptr++ >>= shift;
+            }
+
+        if ((mag -= shift) < 0)
+            flags &= ~MAG_MASK;
+        else
+            flags -= (1 << MAG_LSB) * shift;
+
+        wps->wphdr.flags = flags;
+    }
+
+    if (!pack_samples (wpc, buffer)) {
+        wps->wphdr.flags = sflags;
+        return FALSE;
+    }
+    else {
+        wps->wphdr.flags = sflags;
+        return TRUE;
+    }
+}
+
+// Pack an entire block of samples (either mono or stereo) into a completed
+// WavPack block. It is assumed that there is sufficient space for the
+// completed block at "wps->blockbuff" and that "wps->blockend" points to the
+// end of the available space. A return value of FALSE indicates an error.
+// Any unsent metadata is transmitted first, then required metadata for this
+// block is sent, and finally the compressed integer data is sent. If a "wpx"
+// stream is required for floating point data or large integer data, then this
+// must be handled outside this function. To find out how much data was written
+// the caller must look at the ckSize field of the written WavpackHeader, NOT
+// the one in the WavpackStream.
+
+static int pack_samples (WavpackContext *wpc, long *buffer)
+{
+    WavpackStream *wps = &wpc->stream;
+    ulong sample_count = wps->wphdr.block_samples;
+    ulong flags = wps->wphdr.flags, data_count;
+    struct decorr_pass *dpp;
+    WavpackMetadata wpmd;
+    int tcount, m = 0;
+    ulong crc, i;
+    long *bptr;
+
+    crc = 0xffffffff;
+    wps->wphdr.ckSize = sizeof (WavpackHeader) - 8;
+    memcpy (wps->blockbuff, &wps->wphdr, sizeof (WavpackHeader));
+
+    if (wpc->wrapper_bytes) {
+        wpmd.id = ID_RIFF_HEADER;
+        wpmd.byte_length = wpc->wrapper_bytes;
+        wpmd.data = wpc->wrapper_data;
+        copy_metadata (&wpmd, wps->blockbuff, wps->blockend);
+        free_metadata (&wpmd);
+        wpc->wrapper_data = NULL;
+        wpc->wrapper_bytes = 0;
+    }
+
+    if (!sample_count)
+        return TRUE;
+
+    write_decorr_terms (wps, &wpmd);
+    copy_metadata (&wpmd, wps->blockbuff, wps->blockend);
+    free_metadata (&wpmd);
+
+    write_decorr_weights (wps, &wpmd);
+    copy_metadata (&wpmd, wps->blockbuff, wps->blockend);
+    free_metadata (&wpmd);
+
+    write_decorr_samples (wps, &wpmd);
+    copy_metadata (&wpmd, wps->blockbuff, wps->blockend);
+    free_metadata (&wpmd);
+
+    write_entropy_vars (wps, &wpmd);
+    copy_metadata (&wpmd, wps->blockbuff, wps->blockend);
+    free_metadata (&wpmd);
+
+    if ((flags & INITIAL_BLOCK) && !wps->sample_index) {
+        write_config_info (wpc, &wpmd);
+        copy_metadata (&wpmd, wps->blockbuff, wps->blockend);
+        free_metadata (&wpmd);
+    }
+
+    bs_open_write (&wps->wvbits, wps->blockbuff + ((WavpackHeader *) wps->blockbuff)->ckSize + 12, wps->blockend);
+
+    /////////////////////// handle lossless mono mode /////////////////////////
+
+    if (!(flags & HYBRID_FLAG) && (flags & MONO_FLAG))
+        for (bptr = buffer, i = 0; i < sample_count; ++i) {
+            long code;
+
+            crc = crc * 3 + (code = *bptr++);
+
+            for (tcount = wps->num_terms, dpp = wps->decorr_passes; tcount--; dpp++) {
+                long sam;
+
+                if (dpp->term > MAX_TERM) {
+                    if (dpp->term & 1)
+                        sam = 2 * dpp->samples_A [0] - dpp->samples_A [1];
+                    else
+                        sam = (3 * dpp->samples_A [0] - dpp->samples_A [1]) >> 1;
+
+                    dpp->samples_A [1] = dpp->samples_A [0];
+                    dpp->samples_A [0] = code;
+                }
+                else {
+                    sam = dpp->samples_A [m];
+                    dpp->samples_A [(m + dpp->term) & (MAX_TERM - 1)] = code;
+                }
+
+                code -= apply_weight_i (dpp->weight_A, sam);
+                update_weight (dpp->weight_A, 2, sam, code);
+            }
+
+            m = (m + 1) & (MAX_TERM - 1);
+            send_word_lossless (wps, code, 0);
+        }
+
+    //////////////////// handle the lossless stereo mode //////////////////////
+
+    else if (!(flags & HYBRID_FLAG) && !(flags & MONO_FLAG))
+        for (bptr = buffer, i = 0; i < sample_count; ++i, bptr += 2) {
+            long left, right, sam_A, sam_B;
+
+            crc = crc * 3 + (left = bptr [0]);
+            crc = crc * 3 + (right = bptr [1]);
+
+            if (flags & JOINT_STEREO)
+                right += ((left -= right) >> 1);
+
+            for (tcount = wps->num_terms, dpp = wps->decorr_passes; tcount-- ; dpp++) {
+                if (dpp->term > 0) {
+                    if (dpp->term > MAX_TERM) {
+                        if (dpp->term & 1) {
+                            sam_A = 2 * dpp->samples_A [0] - dpp->samples_A [1];
+                            sam_B = 2 * dpp->samples_B [0] - dpp->samples_B [1];
+                        }
+                        else {
+                            sam_A = (3 * dpp->samples_A [0] - dpp->samples_A [1]) >> 1;
+                            sam_B = (3 * dpp->samples_B [0] - dpp->samples_B [1]) >> 1;
+                        }
+
+                        dpp->samples_A [1] = dpp->samples_A [0];
+                        dpp->samples_B [1] = dpp->samples_B [0];
+                        dpp->samples_A [0] = left;
+                        dpp->samples_B [0] = right;
+                    }
+                    else {
+                        int k = (m + dpp->term) & (MAX_TERM - 1);
+
+                        sam_A = dpp->samples_A [m];
+                        sam_B = dpp->samples_B [m];
+                        dpp->samples_A [k] = left;
+                        dpp->samples_B [k] = right;
+                    }
+
+                    left -= apply_weight_i (dpp->weight_A, sam_A);
+                    right -= apply_weight_i (dpp->weight_B, sam_B);
+                    update_weight (dpp->weight_A, 2, sam_A, left);
+                    update_weight (dpp->weight_B, 2, sam_B, right);
+                }
+                else {
+                    sam_A = (dpp->term == -2) ? right : dpp->samples_A [0];
+                    sam_B = (dpp->term == -1) ? left : dpp->samples_B [0];
+                    dpp->samples_A [0] = right;
+                    dpp->samples_B [0] = left;
+                    left -= apply_weight_i (dpp->weight_A, sam_A);
+                    right -= apply_weight_i (dpp->weight_B, sam_B);
+                    update_weight_clip (dpp->weight_A, 2, sam_A, left);
+                    update_weight_clip (dpp->weight_B, 2, sam_B, right);
+                }
+            }
+
+            m = (m + 1) & (MAX_TERM - 1);
+            send_word_lossless (wps, left, 0);
+            send_word_lossless (wps, right, 1);
+        }
+
+    if (m)
+        for (tcount = wps->num_terms, dpp = wps->decorr_passes; tcount--; dpp++)
+            if (dpp->term > 0 && dpp->term <= MAX_TERM) {
+                long temp_A [MAX_TERM], temp_B [MAX_TERM];
+                int k;
+
+                memcpy (temp_A, dpp->samples_A, sizeof (dpp->samples_A));
+                memcpy (temp_B, dpp->samples_B, sizeof (dpp->samples_B));
+
+                for (k = 0; k < MAX_TERM; k++) {
+                    dpp->samples_A [k] = temp_A [m];
+                    dpp->samples_B [k] = temp_B [m];
+                    m = (m + 1) & (MAX_TERM - 1);
+                }
+            }
+
+    flush_word (wps);
+    data_count = bs_close_write (&wps->wvbits);
+
+    if (data_count) {
+        if (data_count != (ulong) -1) {
+            uchar *cptr = wps->blockbuff + ((WavpackHeader *) wps->blockbuff)->ckSize + 8;
+
+            *cptr++ = ID_WV_BITSTREAM | ID_LARGE;
+            *cptr++ = data_count >> 1;
+            *cptr++ = data_count >> 9;
+            *cptr++ = data_count >> 17;
+            ((WavpackHeader *) wps->blockbuff)->ckSize += data_count + 4;
+        }
+        else
+            return FALSE;
+    }
+
+    ((WavpackHeader *) wps->blockbuff)->crc = crc;
+
+    wps->sample_index += sample_count;
+    return TRUE;
+}